only had a few hands on the vill, though seemed fishy, with small bets and limp calling utg etc .
I remember thinking he could be on a flush draw, and thinking i've also go the back door flush that was one of my reason for calling. But thinking about it if we have the Ace of clubs its unlikely they are on a flush draw... Any thoughts?

Postflop: It's possible that villain has slowplayed some massive hand but these fishy guys usually min raise for value more often than overbet shove (although this shove is not a huge overbet) so my first inclination would be to just call.

Add in the fact that he can have random Kx, AK, QT, some draws and I'm not folding.

Ignoring that and imagining I was in the hand, I get will always be more wary in pots where some-one else is already all-in pre-flop. It makes it less likely (in my eyes) that the opponet will bluff too hard as even if we fold they still have to go to show-down and win to capture the pot.

Originally posted by Philfox1985
I assume he had Jx from the initial comment.

Ignoring that and imagining I was in the hand, I get will always be more wary in pots where some-one else is already all-in pre-flop. It makes it less likely (in my eyes) that the opponet will bluff too hard as even if we fold they still have to go to show-down and win to capture the pot.

Is this a valid concern?

Yes, it could be a valid concern but here I'm not including pure bluffs in his range.

We can include semibluffs (which can be somewhat strong) and made hands (Kx and possibly other pairs).

On NL5 many players are quite scared of these high paired up boards, as hero could have that J there. So guess they are rarely raising there, unless they have a jack or they are very aggressive or good lags/tags. And if he was limp/caller, then it's more likely he is a passive player, who doesn't play his draws that aggressive and raises for value only (with "nuts").